WildfiresActions can change outcomes of wildfires in wildland urban interface (WUI)

Published 10 November 2015

The ten years since 2002 saw an annual average of nearly 71,000 wildland urban interface (WUI) fires recorded and 1.9 million hectares (4.7 million acres) burned. Today, more than 32 percent of U.S. housing units and one-tenth of all land with housing are situated in the nation’s 89 million hectares (220 million acres) of WUI, putting approximately 72,000 communities and more than 120 million people at risk. A new study demonstrates that prompt and effective action can significantly change the outcome of fires that occur in WUI — areas where residential communities and undeveloped wildlands meet.

A California widfire burns through wildland-urban interface // Source: nasa.gov

A new study of Colorado’s devastating 2012 Waldo Canyon wildfire demonstrates that prompt and effective action can significantly change the outcome of fires that occur in areas where residential communities and undeveloped wildlands meet. The study by the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) is the most comprehensive examination in history of a wildland urban interface (WUI) fire.

WUI fires are very different from earthquakes, hurricanes and tornados where the hazard cannot be controlled,” said NIST fire researcher and principal investigator Alexander Maranghides. “Our study showed that WUI fires also are distinct from either urban or wildland fires alone. We provide strong evidence that defensive measures designed specifically for the wildland urban interface and administered early can significantly reduce destruction and damage.”

NIST says that the study found, for example, that because the Waldo firefighters tailored their response to the specific WUI conditions, 75 percent of their attempts to extinguish ignited structures were successful and 79 percent of their efforts at fire containment were successful in preventing rampant fire spread.

The details of the NIST study are described in a report released the other day in Washington, D.C., during the Fire Chiefs White House Roundtable on Climate Change Impacts at the Wildland Urban Interface.  

The number of WUI fires, particularly in the western and southern regions of the United States, has grown as housing developments push into wilderness areas. According to the Bureau of Land Management’s National Interagency Fire Center (NIFC), the ten years since 2002 saw an annual average of nearly 71,000 WUI fires recorded and 1.9 million hectares (4.7 million acres) burned. Today, more than 32 percent of U.S. housing units and one-tenth of all land with housing are situated in the nation’s 89 million hectares (220 million acres) of WUI, putting approximately 72,000 communities and more than 120 million people at risk.  

The physical and monetary toll from WUI fire destruction is staggering. The NIFC calculates that nearly 39,000 homes — more than 3,000 per year — were lost to wildfires from 2000-12 and that federal, state, and local agencies spent an average of $4.7 billion annually during that period on WUI fire suppression.